jbedon.nvc

2 years ago

On the Session 50 Worked Example a (MVT, FTC1 stuff), how did the lower bound equal 1.2? Thanks!

Doesn't matter what the lower bound is as long as the antiderivative (F) is defined at that point. Because the lower point is fixed it yields a constant to the antiderivative and thus after differentiation it's gone.
Example:
\[\frac{ d }{ dx }\int\limits_{1}^{x}\frac{ 1 }{ t } dt = \frac{ d }{ dx } (\ln \left| x \right| - \ln \left( 1 \right)) = \frac{ 1 }{ x }\]
You could substitute any positive constant value in place of 1 and the result would have been just the same.